Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

No annotations are provided, so the description carries the full disclosure burden. It does add real value by naming the statutory ratios the calculation compares against, but it never says what the tool returns (pass/fail, shortfall, computed minimums) or how missing glazed/openable areas are treated.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

A single dense sentence with the standard, the metric, the threshold and the room scope all front-loaded. Every clause carries information an agent would otherwise have to guess.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

With no annotations and no output schema, the description should also describe the result shape and the optional-parameter behavior. It covers the regulatory intent well but leaves the agent guessing what comes back and how partial inputs are handled.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100%, so the baseline is 3, and the description earns an increment by tying the parameters to the requirements: floor area drives the lighting minimum and openable sash area drives the ventilation minimum, with glazed area as the comparison value. It still does not clarify that the two 'actual_*' parameters are optional.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (calculate) plus the exact resource: SANS 10400-O natural lighting and ventilation compliance for habitable rooms, including the statutory thresholds (10% floor area, 5% openable sash). This clearly distinguishes it from the sibling calculate_stair_compliance, which covers a different part of the standard.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

The domain context implies when it applies (checking habitable rooms against SANS 10400-O), but there is no explicit when-to-use/when-not guidance and no mention of alternatives such as check_municipal_requirements or pre_check_building_plan. Nothing tells the agent what to do if only floor_area_m2 is supplied.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.